In conference and meeting presentations, a presenter often uses a laser pointer to illuminate and highlight portions of a projected viewgraph or slide presentation so that an associated oral message can be better understood by the audience. The conventional laser pointer projects only a small bright spot. The typically small-sized spot is difficult to be distinguished when projected upon a large screen. Another disadvantage for a laser pointer often is the brightness of the spot, so that can make viewers very uncomfortable if their eyes inadvertently focus on the spot.
An illuminated spot may also be used to assist in the aiming of a firearm for improving targeting accuracy during hunting. The small size of the laser mark can also be a disadvantage as it is difficult to be noticed far away.
A few modified laser pointers have been developed. For example, U.S. Pat. No. 5,450,148 uses a set of selectable masks to filter a magnified laser output into a desired pattern. U.S. Pat. No. 5,400,514 teaches a way to create light geometric tracing through moving a light source in one or two dimensions. Refer to U.S. Pat. No. 6,789,922, a transverse columnar faceted lens is used to refract a laser beam into a cross-shaped beam laser ray. U.S. Pat. No. 5,938,308 teaches the usage of a plastic holographic optical element or a diffractive optical element for projecting light into an image on a remote target. U.S. Pat. No. 7,971,790 illustrates a laser pointer that its pattern and size of the projected image can be controlled by a human-machine interface. The image is produced by passing a laser beam through a light scanning device, such as a mirror. A frequency/phase control module and a driving energy control module control the movements of the light scanning device. The human-machine interface can be designed as a push button or rotary switch for users to select and operate the laser pointer. U.S. Pat. No. 8,896,899 creates circular or elliptical patterns through a laser beam reflection off a tilted rotating mirror. These modifications have clearly provided new optical patterns beyond a simple dot, making them easier for the audience to notice. However, none of the above solutions allow users to adaptively change the optical pattern size for precisely matching the physical dimension of the intended area of the informational contents, such as charts or texts, on a projection screen.